This invention relates to an arrangement for providing electrically transparent selectable connections in a communications system.
The invention will be described with reference to the connection of subscriber lines to exchange lines, such as at a xe2x80x9cpillarxe2x80x9d or street connection box, or at an exchange, although the system is also suitable for use for connecting other types of lines such as ADS lines connecting a set-top box to a programme distribution centre.
Currently, subscriber line to exchange line connection is performed manually using jumper leads. Because the connections are done manually, the connection points must be large enough to facilitate manual connection.
An additional disadvantage of this system is that a technician must be at the location of the connection box to carry out the connection.
This specification discloses an array of individually controllable contacts to enable any one of a first group of points to be connected to a selected one of a second group of points, wherein the contacts are implemented in micro-machine technology and form electrical contacts which are substantially transparent to electrical signals.
In a preferred embodiment, each of the individually controllable contacts includes remotely actuable control means to controllably open and close the associated contacts.
In one embodiment, for a bi-stable switch, the contacts include first and second fixed contacts and a movable contact, such as a contact armature which includes magnetic material and is associated with a permanent magnet to latch the armature in a first position, wherein controllable heating means are provided to heat one of the contacts to or above the Curie temperature of the magnetic material, the armature being resiliently cantilevered or pivotally mounted to move to a second position when the armature is de-magnetized.
In an alternative embodiment, the armature is operated electro-mechanically.
In a further embodiment, the armature is operated by piezo-electric actuator means.
While remote switching can be performed using semiconductor switches, the device of the present invention has the advantage that the mechanical contacts are effectively electrically transparent, the implementation in micro technology providing the advantage of small size and the ability to remotely control the switching of the contacts.